Reducing Marine Biofilm Formation via Surface Modification: Supporting Seagrass Restoration

The formation of biofilms on man-made surfaces is a common and problematic occurrence in the marine environment. In addition to man-made surfaces, biofilm formation can also appear on naturally occurring marine surfaces, such as sediment and rock substrates and plants. The commencement of a seagrass restoration project in South Australian waters has developed an approach to utilise natural hessian material to assist in seagrass recruitment. However, it is believed that biofilm formation may be a contributing factor in the degradation and longevity of this hessian material. In this context, we investigated the modification of hessian material using different coatings types to (i) reduce biofilm formation and (ii) extend hessian life. Our initial results, using flow cytometric analysis, indicated a reduction in virus like particle (VLP) and heterotrophic bacterial abundance between untreated and phenyltrimethoxysilane (PTMS) coated hessian. Furthermore, the cytometric sub-group formation of VLPs and heterotrophic bacteria exhibited distinct changes between coatings. The identification of bacteria within the formed biofilm on each hessian bag was also carried out using 16S pyrosequencing. These results highlighted marked changes in community composition between different coating types. This study provides an understanding on how the modification of hessian surfaces can alter the abundance and composition of the bacterial community formed in the associated biofilm, generating valuable information for further studies into antifouling in the marine environment.